Why Multiple Sessions Are Needed with Laser Hair Removal

When people come in for a laser hair removal consult, they will often think that the process is going to be completed with 1 or 2 treatments. This blog was been written in a very simplistic manner to help give some understanding of the hair cycles, which in turn will help to understand why it is not possible to eliminate unwanted hair with only 1-2 treatments.

Hair grows at the root in a bulb called a follicle.  Hair on the human body grows and sheds in cycles. There are three cycles that hair goes through as follows:

Anagen Phase Active growth phase: 2-6 years-The hair grows actively and contains an abundance of melanin.

Catagen Phase Transitional Phase: 2-3 weeks-The hair stops growing, and the follicle separates from the base.

Telogen Phase Resting Phase: The hair follicle remains dormant for 2-4 months before falling out and is replaced by the new hair.

Hair on the head and the body go through the same cycles, however hair on the body moves through the cycles much more rapidly.  This prevents the hair on our body from getting too long, while the hair on our head can grow longer. Body hair only grows for about 30-45 days in comparison to hair on the head, which grows from 2-6 years during the anagen growing stage.

Since the hair follicle is detached in the catagen and telogen phases, there is nothing for the laser to target, and the laser will have no effect on it.  The laser will only target and damage hair follicles in the anagen stage because the root is still attached, and it contains the melanin that the laser light absorbs.

The complete cycle of hair growth is also why laser hair removal may not be 100% permanent, and touch ups may be needed.  Each person can expect different results depending on the type of hair they have. Thick and course hair will achieve a greater rate of reduction rather than fine hair.

Last, you should not pluck, wax, or bleach unwanted hair, as it interferes with the hair follicle. In order to see hair elimination and reduction, the follicle needs to remain intact, with pigment for the laser’s energy to target and kill the follicle.